Window frame insulating means



Feb. 18, 1964 H. N. COBB ETAL 3,121,482

WINDOW FRAME INSULATING MEANS Filed Oct. 25, 1961 2 Sheets-Sheet 1 IIIII `IIHLIQ mi.

IIN IIIIHI ,.IIIIIIIIIIII "n.IIIIIIIIII" I ATTOR NEYS Feb. 18, 1964 H. N. COBB ETAL 3,121,482

WINDOW FRAME INSULATING MEANS Filed Oct. 25. 1961 2 Sheets-Sheet 2 ATTOR N United States Patent O 3,121,432 WENDUW FRAME lNSUlLATlNG lli/IEANS Henry N. Cobb, New York, and Pershing Wong and Martin Daum, Westchester County, N.Y., assgn'ors to Webb d: Knapp, a corporation of Delaware Filed Oct. 25, 1961, Sei'. No. 147,541 6 Claims. (Cl. 1259-64) This invention relates to thermal insulating means for use in building construction and, more particularly, to gasket means for thermally insulating the interior surfaces of heat conductive window frames. The invention is directed especially to the creation of a thermal barrier over all exposed interior surfaces of window frame elements in metal and glass curtain wall panel assemblies.

Conventional window frames are exposed both to outside weather conditions and to room conditions within their building, and when they are of metal or other relatively high heat conductive materials their interior surfaces are at a temperature close to that of the outside air. ln colder climates, window frames of this type are easily chilled to a low temperature, with the result that condensation and even severe frost collects on the frame elements exposed to room temperature and humidity. These conditions are distinctly undesirable because they require measures such as drainage systems and the like to carry off the condensation and melted frost, they increase the burden on the buildings heating system, and they create an unfavorable appearance when the condensation or frost developes to a visible extent.

Problems of this sort are particularly severe when metal and glass curtain wall panel assemblies are used to form the exterior of a building. Such panel assemblies generally include a Window and panel portion and are mounted in place between spaced vertical mullions. The window is surrounded by a metal frame which is usually anchored at its vertical side portions to the adjacent mullions. From floor to ceiling within the building, the window comprises the greatest part of the wall section defined by each panel, with the frame, mullions, and window and frame fasteners forming the remainder of the wall section. Ordinarily, elongated sections of metal are used to cover the mullions and fasteners but they are conventionally in direct metal-to-metal contact with the frame and hence are also chilled by the outside air. Sometimes laminar gaskets are compressed between parts of the frame but they contribute very little to the thermal insulation of the interior surfaces of the frame and metal sections covering the mullions and fasteners. Such compressed gaskets must be made of mechanically strong materials because of the high loads which they bear, and this involves a substantial compromise in insulating properties. Also, typical compressed types of window trarne gaskets are pierced by bolts or other fasteners which make additional direct metal-to-metal contact with the exteriorly exposed parts of the frame and thus further chill the inner metal parts overlying the gaskets.

It is the primary purpose of the present invention to provide a thermal barrier disposed over the inside surface of a heat conductive window frame such that it defines an interior surface in substantially complete isolation from the chilled outer parts. The frame or the like with which the new thermal barrier is to be used is exposed on the exterior and interior of a building structure. (By exposed on the exterior it is meant that the frame is in substantial direct metal-to-metal contact with surfaces exposed to outside air; and by exposed on the interior it is meant that its interior parts are uncovered prior to installation of the new thermal barrier.) Broadly stated, the thermal barrier of the invention comprises a gasket of insulating material adapted to overlie the uncovered portions of the frame on the interior side thereof. This ICC gasket is self-supporting and attachable tothe frame without bearing substantial applied stresses. Hence, the gasket may be easily attached from the inside of the building after the window frames have been put in place and, more importantly, it may be made of a material chosen solely for its thermal insulating properties without undue regard for mechanical strength.

In a preferred form, the gasket may have a groove formed on the backside thereof to dene an air space over part of the uncovered portions of the frame. This air space is made possible because of the substantially load-free design of the gaskets and it is advantageous in that it further insulates the chilled metal frame parts. -In conventional laminar window frame gaskets, it is not feasible to provide such an air space because of the high compressive forces to which such ordinary gaskets are subjected. The new gaskets may also include a resilient slotted portion for grasping the frame and releasably holding it in place.

t is also provided by the invention that the new thermal barrier be used in combination with a curtain wall panel assembly including a window frame exposed on the interior and exterior sides of the assembly. The frame may include a flange extending inwardly between a rim and window fasteners. The assembly may also comprise exterior vertical mullions to which the rim on the vertical sides of the frame is attached. Pursuant to the invention, the new thermal barrier may comprise the aforementioned gasket covering part of the ange and rim and, along with a second gasket, it may also provide an insulated seat for metal sections which cover the inside of the mullions and the window fasteners.

A preferred embodiment of the invention is described below with reference to the accompanying drawings,

' wherein FIG. l is an exterior elevation of one complete panel assembly operatively positioned along with other such panels between mullions on the outside of a building;

FIG. 2 is a fragmentary section taken along the line 2 2 of FIG. l at the upper portion of the window frame;

FIG. 3 is a fragmentary section taken along the line 3-3 of FIG. l at the lower portion of the window frame; and

FIG. 4 is a fragmentary section taken along the line 4-4 of FIG. l at the side portion of the window frame and adjacent mullion.

Referring first to FIG. l, the curtain wall panel assembly includes a glass window 16 and a panel 11 of metal. Surrounding the window 1t? is a metal frame which includes vertical side portions 12 and 13, an upper edge portion 14, and a lower edge portion 15. The frame side portions 12 and 13 extend upwardly alongside the metal panel 11 to an uppermost panel frame portion 16 which defines the upper edge of the assembly. The entire panel assembly is mounted between, and may be said to include, vertical mullions 17 and 18 which are anchored to the building structure. Both the window it) and panel 11 are proportioned such that the panel 11 substantially spans the floor structure of the building while the window lil extends downwardly substantially from the adjacent ceiling to the next lowest door,

As shown in each of FIGS. 2-4, the window `liti is covered about its periphery by a U-shaped gasket 20, advantageously of neoprene, which `is continuous and snapped in place. Each of the four sides of the window is held in the respective portions of the frame by a plurality of separate small window fasteners 21 which are turned down about a fulcrum portion 22 by means of a bolt 23 such that an abutting portion 24 presses against the gasket 20 to hold the window in place. These window fasteners 21 are on the interior side of the panel assembly.

The vertical side portions 12 and 13 of the frame 'are attached to their adjacent mullions by the frame fasteners shown in FIG. 4. The mullions include a channel base portion having inwardly extending flanges 26. By means of spaced studs 27, a plurality of lateral brackets 23 are screwed tightly against the flanges 26. In each bracket 28, a pair of slots is provided for receiving the heads of screws 29 which extend inward-ly into the channel base portion 25 of the mullion. These screws 29 are fitted through respective spaced clamps 30 which span the backside of the base portion 25. The outer ends of the clamp 30 extend over the flange portions 26 of the mullion base and grip a rim 32 on the adjacent frame portion 12. By turning nuts 33 down on the respective screws 29, the frame is secured tightly in place.

Turning now to each of FlGS. 2-4, it is apparent that `all of the frame portions `lZ-l are of somewhat similar construction. Each includes a rim, an inwardly extending flange, and a lip for holding the window. Thus, in FIG. 2, the upper frame portion 14 includes a llange 35 extending inwardly between a rim 36 and a lip 37; in FIG. 3, the lower frame portion l5 includes an inwardly extending flange 39, a rim 4d (which is a separate part but is attached in direct metal-to-metal contact to the remainder of .the frame portion 15), and a lip 41; and, in FIG. 4, the side f-rame portion 12 includes an inwardly extending flange 43, the already mentioned rirn 32, and a lip 44. In each of these frame portions, the window fasteners 2d are screwed into a base portion on the associated ange 35, 39' or 43.

Viewed from the interior of lthe building, the window lo extends almost from the floor to the ceiling between the mullions. However, without any further structure other than that already described, substantially all of the frame portions, various window and frame fasteners, and the inside surface of the mullions are fully exposed. Along the top of the window, a venetian blind well 46 terminates above :the `flange of the upper frame portion :14 so that the rim 36 thereof is visible. At the bottom of the window, an induction heater 47 cornes to just below the flange 39 of the lower frame portion l5 without covering the rim 4t) thereof. To each side of the window, of course, the interior surface of the mullions and the frame fasteners are in full view.

As provided by the invention, a gasket 5d of substantially L-shaped cross section is used to cover each rim and the side of the associated flange nearest thereto on each of the window frame por-tions. The gasket Sti may be in four separate lengths, perhaps beveled at the joints, to cover the four respective portions of the frame. However, the flange 50 has a substantially L-shaped cross section which is uniform on al1 of the frame portions. Therefore, it will be described and claimed herein as if it were (and indeed it may be) of continuous unitary construction. The gasket 5d is formed with two grooves 51 and 52 on its backside, one on each leg of its L-shaped cross section. These grooves dene air spaces over the respective flanges 35, 39 and 43 and the respective rims 36, and 32, thereby vastly increasing the thermal insulating effect of the gasket 50. Also, the gasket is formed with a slotted portion 53 adapted to be snapped over the edge of the respective flanges 35, 39 and 43 to hold the gasket releasably in place. It is important to note that the gasket 5@ does not bear any substantial applied stresses when snapped in place on the frame and thus may be formed from a material chosen primarily for its insulating properties without undue regard for mechanical strength. Neoprene has proven to be advantageous in this regard. The design of the gasket 5@ also permits it to be applied with great ease simply by laying it over the edge of the window frame flanges after the curtain wall is installed.

As shown in FIGS. 2 and 3, the slotted portion 53 of the gasket 50 also provides a thermally insulated seat for one edge of a window fastener cover 55 made up of elongated metal sections. Pour sections of the cover SS extend along the respective four portions of the frame and fully enclose and define an air space about the window fasteners 2l. The other edge of the metal sections providing the cover 55 is seated against continuous gaskets 56 and 57 of circular cross section extending from one window fastener 21 to the next on opposite sides of the outer end portions thereof. Each section of the cover 55 is provided with a slotted edge 59 which fits over the two gaskets S6 and 57 and is held in place thereby. By this construction, the various sections of the cover 55 are insulated along one edge by the gasket 50 and along the other edge by the pair of gaskets 56 and 57. Small clips 53 associated with the window fasteners 21 are used to secure the sections of the cover 55 in place securely.

in FIG. 4, means are shown for extending the thermal barrier over the frame fasteners and the inside surface of the mullions. A plurality of widely spaced clamps et?, secured to the respective brackets 2S by screws 61, hold a mullion cover 62 in place against the inside surface of each mullion. The cover 6-2 is an elongated channellike metal section seated along its opposite edges on the edge portions of the adjoining gaskets S0. Advantageously, a seal 63 is applied between the respective flanges of the cover 62 `and the corresponding gaskets 50. This seal may be a butyl elastomer. The cover 62 defines a space over all the frame fasteners and also over the interior exposed surfaces of the mullion and within that space a filler of fibrous insulating material 64 may be provided to increase the covers insulating effect. Tapered surfaces o5 on the ends of each clamp 6d permit the cover 62 to be installed simply by pushing it against the clamps to force the cover flanges resiliently outwardly until they snap into place.

From the foregoing description it is evident that there is no direct metal-to-metal contact from the exteriorly exposed elernents of this curtain wall panel assembly to the parts thereof exposed between floor and ceiling to room conditions (except through the completely inconsequential paced clips 53 and clamps dii). The gasket 5i) and fastener cover 55 extend from the ceiling (at the well 46) downwardly to the window 6@ as shown in FiG. 2 and from the floor (at the heater 47) upwardly to the window lll as shown in HG. 3; and, along with the mullion cover 62, they extend from one window lll to the next across the mullions as shown in FIG. 4. The various interior surfaces defined by these elements are effectively isolated from the window frame and all the other outside parts which become chilled during cold weather. Thus little, if any, condensation and no frost collects thereon even during extremely cold outside temperatures. The gasket Si) is designed to be easily applied, to be of the most beneficial insulating material, to be formed with the grooves 5l and 52 which provide the optimum insulating effect, and to at least partly seat and thermally insulate the covers 55 and o2.

We claim:

l. In combination with a curtain wall panel assembly including a window frame having a flange extending inwardly between a rim and window fasteners on the interior side of the assembly and having other portions exposed on the exterior side of the assembly, a thermal barrier comprising a first gasket of insulating material overlying the edge and side of said flange nearest said rim and a portion of the adjacent rim, said first gasket being self-supporting and free of substantial applied stresses, elongated metal sections seated at one edge on the portion of said rst gasket overlying the edge of said liange and covering said window fasteners, and at least one second gasket supported by said window fasteners and upon which the other edge of said sections is seated, whereby said sections and said first gasket overlie the uncovered portions of said frame on the interior side thereof.

2. A curtain wall panel assembly according to claim l wherein said first gasket has grooves formed on the backside thereof to define an air space over a portion of said side of said fiange nearest said rim and over a portion of said rim.

3. A curtain wall panel assembly according to claim 1 wherein said first gasket is of elastomeric material and includes a resilient slotted portion which is snapped over the edge of said flange to hold said first gasket rcleasably in place.

4. In combination with a curtain wall panel assembly including a window frame having a ange extending inwardly between an adjoining rim and window fasteners on the interior side of the assembly and having other portions exposed on the exterior side of the assembly, said assembly also including exterior Vertical mullions to which the rim on the vertical sides of the frame are attached by frame fasteners, a thermal barrier comprising a first gasket of insulating material overlying the edge and side of said flange nearest said rim and a portion of the adjacent rim, said first gasket being self-supporting and free of substantial applied stresses, first elongated metal sections seated at one edge on the portion of said first gasket overlying said rim on the vertical sides of the frame and covering the interiorly exposed portions of the mullions and frame fasteners, second elongated metal sections seated at one edge on the portion of said first gasket over- 25 lying the edge of said flange and covering said Window fasteners, and at least one second gasket supported by said Window fasteners and upon which the other edge of said second sections is seated, whereby said first and second sections and said first gasket overlie the uncovered portions of said frame and mullions on the interior side thereof.

5. A curtain wall panel assembly according to claim 4 wherein said first gasket has grooves formed on the backside thereof to define respective air spaces over a portion of said side of said ange nearest said rim and over a portion of said rim.

6. A curtain wall panel assembly according to claim 4 wherein said first gasket is of elastomeric material and includes a resilient slotted portion which is snapped over the edge of said liange to hold said first gasket releasably in place.

References Cited in the file of this patent UNITED STATES PATENTS 2,706,541 Crown Apr. 19, 1955 2,781,111 Kunkel Feb. 12, 1957 2,933,779 Delaroche Apr. 26, 1960 FOREIGN PATENTS 771,181 Great Britain a Mar. 27, 1957 

1. IN COMBINATION WITH A CURTAIN WALL PANEL ASSEMBLY INCLUDING A WINDOW FRAME HAVING A FLANGE EXTENDING INWARDLY BETWEEN A RIM AND WINDOW FASTENERS ON THE INTERIOR SIDE OF THE ASSEMBLY AND HAVING OTHER PORTIONS EXPOSED ON THE EXTERIOR SIDE OF THE ASSEMBLY, A THERMAL BARRIER COMPRISING A FIRST GASKET OF INSULATING MATERIAL OVERLYING THE EDGE AND SIDE OF SAID FLANGE NEAREST SAID RIM AND A PORTION OF THE ADJACENT RIM, SAID FIRST GASKET BEING SELF-SUPPORTING AND FREE OF SUBSTANTIAL APPLIED STRESSES, ELONGATED METAL SECTIONS SEATED AT ONE EDGE ON THE PORTION OF SAID FIRST GASKET OVERLYING THE EDGE OF SAID FLANGE AND 